Stapling machine anvil with removable clincher



Julie l5 1954 w. scum-'ROTH 2,680,845

STAPLING MACHINEy ANvIL wrm REMovABLE CLINCHER Filed May 11, 1953 A /fvnewrme' Patented June 15, 1954 GFFICE STAPLING MACHINE ANVIL WITH REMOVABLE CLINCHER Werner Schafroth, Herrin, Ill. Application May 11, 1953, Serial No. 354,279

This invention relates to anvils used in stapling machines in general, and particularly those of the type which are used to secure the flaps or ends of closed cartons or containers where stationary anvils cannot be used and where Inovable anvils are used for penetrating the material and clinching staples. More particularly, this invention relates to an anvil having an anvil base with a clincher or hook removably secured thereto.

This invention contains subject matter in common with my copending application, Serial No. 340,443, filed March 5, 1953, entitled Stapling Machine.

Prior anvils were provided with clinchers which were made integral with the anvil base, i. e., the hub and shaft. Such an integral or one-piece construction is shown in Figure 5 of Schafroth Patent No. 2,469,054 dated May 3, 1949, in Fig. 6 of Schafroth Patent No. 2,459,055 dated May 3, 1949, and in Fig. 4 of Schafroth Patent No. 2,470,727 dated May 17, 1949. This integral construction is diiicult to make, requires many separate operations, and must be replaced in its entirety when only the clincher or piercing end is broken or worn. Replacement of this small part requires disassembling of a substantial portion of the machine by a factory trained repairman. In addition to these disadvantages, there is a further and more important disadvantage in that each of the three main portions ofthe device,

i. e., the shaft, the hub, and the clincher, should preferably have diierent metallurgical characteristics which cannot be fully met in an integral or one-piece construction. The result is that the characteristics of one portion must be compromised with the characteristics of the other portions. In addition, the integral construction is made from a forging which necessarily results in improper grain structure in the clincher and renders said clincher particularly susceptible to breakage. In practice, the shaft and hub seldom if ever need to be replaced because of wear or breakage.

One of the principal objects of the presentv 11 Claims. (Cl. 1 2) Another object is to provide an interchangeable or reversible clincher which can be secured to either the left anvil base or the right anvil base thereby eliminating the necessity of keeping two different types of relatively expensive one-piece replacement anvils on hand for repair purposes.

Another object is to provide a clincher which can be removably secured to the anvil base, or hub and shaft, of a rotary anvil or to a pivotally mounted handle.

Another object is to provide a clincher which has a longer life expectancy or service period than clinchers previously used.

A further object is to provide a novel clincher construction wherein a new clincher can be substituted for a worn out or broken clincher by the operator himself without removing the shaft or hub of the anvil from the stapling machine. In addition, a new clincher of a different size and shape can be easily substituted for the clincher required for the previous closing or fastening job.

A still further object is to reduce the cost of maintenance and the price of repair parts by providing a separate clincher, which is the most likely part to wear or break, removably secured to the anvil base, which is less likely to break and which requires skilled maintenance men to replace, thereby reducing the price of the replacement part, the time required for replacement, and allowing it to be made with the precise desired characteristics.

These and other objects and advantages will become apparent hereinafter.

This invention is embodied in an anvil construction comprising a shank or shaft and a hub portion with a clincher or hook removably secured thereto. Y

The invention also consists in the parts and in the arrangements and combinations of parts hereinafter described and claimed. In the accompanying drawings which form part of this specification and wherein like numerals and symbols refer to like parts wherever they occur:

Fig. l is a side elevation view of a forging blank from which the old one-piece anvil was made,

Fig. 2 is a perspective view of a one-piece rotary anvil made from the forging blank shown in Fig. l,

Fig. 3 is an exploded perspective view of the present invention showing an anvil cap screw which removably secures the clincher to the integral hub and shaft,

Fig. 4 is an end elevational View of Ithe left anvil base of a set of cooperating anvils in a stapling machine, f

Fig. 5 is a side elevational view of said left anvil base,

Fig. 6 is an end elevational view of the right anvil base,

Fig. 7 is a Side elevational vieiv of said right anvil base,

Fig. 8 is a side elevational View of the new clincher positioned to be placed on a left hub and shaft,

Fig. 9 is an end eleva-tional view of the clincher shown in Fig. 8,

Fig. 10 is a side elevational vievv of the side opposite that shown in Fig. 8 and positioned to be placed on a right hub and shaft,

Fig. 1l is a side elevational viev1 of the clinohe shown in Fig. 8 secured to a left anvil ibase, and

Fig. 12 is a modified form of the invention and comprises a separate clincher adapted to be secured to a pivotally mounted handle.

Referring now to the drawings in detail, it

will be seen that the old or crier onepieoe rotary anvil construction P is shown in Fig. 2 and the forging blank F from which it is made Vis shown in Fig. l. The forging piani; comprises a circular shaft or shank i having circular base 2. The finish-.ed one-piece rotary anvil P comprises a shaft 3 having an integral table portion 4 and clincher 5 thereon. The clincher 5 is provided With an inner or clinching surface d and a piercing end The anvil l? is shown in the Schafroth patents hereinbefore identified.

This old onepiece construction is expensive to make and must be made ,from a costly forging F as a raw material. The anvil P has -three main portions, each of which should have certain speciiic metallurgical characteristics. For eX- ample, the shank or shaft 3 should be made fron a hard metal best suited for use in bearings. The shaft 3 should preferably have a tough core. The table portion l! should preferably be a. hard abrasion resisting surface since each staple slides against said surface i as does the driving blade of the stapling machine, neither of which are shown herein. Thus, whenever a staple is driven, the staple and the driving surface slide against the table portion Il. The clincher 5 itself must be tough and have spring-like characteristics, that is, it must he resistant to fatigue. The clincher' 5 should preferably he made from spring steel or the like, which would be too soft for use either as the table portion @i or the shaft 3.

Or" necessity, the heat treatment of the old onepiece anvil P must be fairly uniform which results in aoompromise as to the characteristics desired in each of the three main portions. in other Words, the quality desired in the shaft 3, and in the table portion Zi, namely, great Wear resistance, must be com-promised with the quality desired in the clincher which should be springlike in character, rather than hard as the shaft 3 and table portion d should lee. In addition, because of the mushroom effect obtained in the original forging B, the grain structure in the clincher 5 is improperly positioned for the high stresses encountered oy the clincher e. In other words, it might be said that the grain structure of the clincher El in a one-piece construction runs in the wrong direction.

The processing of the old one-piece anvil P is extremely difficult and forging dies of various sizes lmust be used because there are various anvil sizes. These sizes are governed by the size 0f the stapling machine and the particular joh which it is to perform. The one-piece anvil P requires a suitable raw materiahsuch as hot rolled chrome molybdenum steel, which must 'oe ordered many months in advance because of drop forge schedules. The forgings must be carefully annealed. The blanks are then turned on turret lathes to face and turn the shaft and hase, and to face and turn the table portion and clincher. The shaft and shoulder centerless ground, and the front face of the clincher is surface ground. The clincher and table portion are proiiled and contoured. The anvil is then deburred and heat treated. The shaft is finished to its proper sise and a multiplicity of grinding operations are performed on the clincher to form the proper cutting and clinching surfaces. The staple clinching surface is polished and the entire one-piece anvil P is inspected.

In addition to the inherent physical disadvantages of a one-piece construction and the diiculty of making said construction, it is equally unsatisfactory from the viewpoint of servicing and replacement because the stapling machine must loe dismantled to a great extent in order to install a replacement anvil P when only the clincher 5 itself is actually broken or worn. In the case of a multiple head powered stapling unit wherein some heads are installed beneath a conveyor, it usually takes an experienced factory service man at least an hour to make a replacement. The operator, or even a relatively experienced house serviceman, requires a much longer period of time. All this is required even though the shank 3 itself is not broken, but it must be replaced every time a clincher 5 is broken since the tvvo are integral and part of a onepiece construction. In addition, Whenever one of the one-piece anvils of a multiple head powered stapling machine is Worn or broken, it renders this entire expensive piece of production equipment useless for a relatively long period or" time thereby interrupting production schedules.

Referring now to the new two-piece construction shown in Figs. 3-12, the invention is embodied in a two-piece anvil construction A wherein an anvil cap screw E having a hexagonal opening 9 therein removably secures the separate clincher C to an anvil base B comprising a shaft lil and a hub I l. Two cooperating rotary anvils must be used in each stapling machine to clinch the two ends of each staple. A pair of anvil bases B is best shown in Figs. -7. Each anvil base B' is provided with a shaft I0 having a hole i2 therethrough. A chainfer I3 is provided at the end of the shaft I@ and a groove i4. at the opposite end which is adjacent to the hub Il which is substantially a quadrant of a circle. The hub il comprises a clincher securing portion i5 and a table portion i6. The clincher securing portion l5 is provided with tivo holes Il and I8 having tvvo anvil pins le and 2i) secured therein, and a tapped hole 2l. That portion of the hub Il which is not covered by the clincher C is referred to as the table portion i6 over which staples and the driving blade of the stapling machine slide.

The clincher C, as best shown in Figs. 8-10, can be secured to either a left anvil base as shown in Figs. 4 and 5, or to a right anvil base as shown in Figs. 6 and 7. The new clincher C has 'two flat sides 22 and 23. The clincher C has an upper portion 24 which is provided with two anvil pin holes 25 and 26 and an anvil screw hole 2l, which is countersunk on both sides, as at 28 and 29. The upper portion 2d also has a slopingr top edge 3Q and a beveled corner 3 i The clincher C has a piercing and clinching end 32 and an intermediate body portion 33 betweenfsaid piercing and 24. The clincher C is provided with a curved vouter edge 34 and a sloping straight end portion 35. The inner edge 36 comprises a straight portion 31 which cooperates with the sloping straight end portion 35 to form a piercing edge 38. In- Wardly of said straight edge portion is a curved portion 39 which connects with an intermediate straight portion 40 which is joined by a large curved portion 4i which connects with a large rounded semicircular portion 42 having a reversely curved portion 43 adjacent thereto. The semicircular portion 42 should have the largest possible radius of curvature since it is adjacent to an area wherein a failure might occur.

'I'he new clincher C is shown in assembled relation with the anvil base B in Fig. 11.

A modified form of the invention is shown in Fig. 12. 'I'he modied form C" is adapted tol be secured to a pivotally mounted handle as shown in my copending application, Serial No. 340,443, led March 5, 1953, as distinguished from the form shown in Figs. B-ll which is adapted to be used in a machine using rotary anvils as shown in the hereinbefore mentioned Schafroth patents. The modied clincher C" comprises an upper securing portion 24 having two anvil pin holes 25' and 26 therein and a tapped hole 21' which is countersunk on both sides or surfaces. The clincher C' is provided with a piercing end 32 and with an intermediate body portion 33 between said piercing end 32 and said upper securing portion 24. The curved outer edge 34 is beveled on both sides, as at 412, thereby terminating in a piercing point 38. The inner edge 3B' of the clincher C is curved, as at 45, in the piercing end portion 32 and terminates in a steeply curved portion 46 which connects with an intermediate curved portion 41 having a semicircular portion 42' adjacent the upper securing portion 24. The clinching inner curved surface 45 is flat and is approximately the Width of a staple.

The processing of the new anvil A including its separate anvil base B and clincher C is exf tremely simple. To form the anvil base B, a one inch diameter cold iinish steel blank is turned to form the shaft I and hub H. The holes I1, I8, and 2li are drilled and tapped in one operation. All surfaces are carburized simultaneously,

and the base is centerless ground to finish. The clincher C is ground to thickness from raw spring steel and holes 25, 25, and 21 are drilled. The clincher is tumbled to remove any burrs. The

actual staple clinching surface 36 is milled. The

clincher is then heat treated in a lead bath and polished. The purpose of the heat treatment is to impart to the clincher the desired and necessary qualities for good performance and long life, including the proper arrangement of grain structure.

Accordingly, the clincher C'is easily fabricated from the proper metal, and the anvil base B is fabricated easily from a diiferent kind of metal. Thus, each main component part has the desired inherent metallurgical characteristics which do not have to be compromised in any way.

The practical advantages of the new separate clincher construction are many. The blanks used for the new clincher C and for the anvil base portion are relatively cheap and'geach can be made from material having the proper characteristics for the desired end results, that is, the anvil base can be made from hard abrasion resisting material. The clincher can be made from at spring steel stock which is resilient and resistant to fatigue. Each part is relatively easy and cheap to make. With the separate crescentshaped clincher, the grain structure is properly oriented and runs longitudinally and substantially parallel with the geometric axis instead of transversely across said clincher, as in the prior onepiece constructions. The general direction of the grain structure is indicated by the arrows in Figs. 2, 8, and 10. The problem of replacement is greatly simplied and eliminates the necessity for factory trained repairmen, and for the user to keep an inventory of its diierent types of rotary anvils, both left and right. As previously indicated, different sizes and shapes of anvils are sometimes required depending upon the particular job tc be performed, and the present invention allows the clinchers to be changed quickly and immediately by the operator himself in a very short period of time.

To replace a clincher, part of the stapling casing is removed by simply removing two to four screws thereby exposing the clincher and the anvil cap screw B which is removed. A new clincher is substituted for the broken or worn out clincher. The cap screw is then replaced. As indicated, the clincher, which is the subject of the present invention, may be used either as a left or right clincher.

This invention is intended to cover all changes and modiiications of the example of the invention herein chosen for purposes of the disclosure, which `do not constitute departures from the spirit and scope of the invention.

Y What I claim is:

l. A removable and reversible substantially crescent-shaped clincher for a stapling machine having a pivoted member for receiving said clincher, said clincher having two flat sides and comprising an upper securing portion having a sloping top edge anda plurality of holes therein, a piercing and clinching portion extending therefrom, said latter portion being of less width than said upper securing portion and having a piercing means therein, said clincher having its grain structure running in a direction substantially parallel to the geometric axis of said clincher. 2. A removable and reversible substantially crescent-shaped clincher for a stapling machine having an anvil base therein, said clincher having two at sides and comprising an upper securing portion having a sloping top edge and a plurality of holes therein, at least one of said holes being countersunk, an intermediate body portion adjacent said upper securing portion, said intermediate body portion being of less width than said upper securing portion, a piercing and clinchingportion adjacent said intermediate body portion, said latter portion being of less width than said intermediateportion and having piercing means therein, said clincher being made from spring steel and having its grain structure running in a direction substantially parallel to the geometric axis of said clincher.

3. A rotary anvil base made from hard abrasion resisting metal and adapted for use in bearings, said anvil base comprising a shaft with a hub thereon, said hub having a flat surface thereon perpendicular to the axis of said shaft, said at surface including a clincher securing portion and a table portion,said clincher securing portion having a threaded hole therein and two anvil pins extending outwardly from said flat surface in a direction parallel to the axis of said shaft.

.4. A Arotary anvil base Yfor a rotary :anvil in a stapling machine, said base being madeV from hard abrasion resistingy metal and adapted for use in bearings, said base comprising a cylindrical shaft having a hole therein and a substantially quadrant shaped hub thereon, said hub having a flat surface thereon opposite said shaft and perpendicular to the axis of said shaft, said dat surface opposite said shaft including a clineher securing portion and a table portion adjacent thereto, said clincher securing portion having a threaded hole therein adjacent the circumference of said quadrant shaped hub and a pin extending outwardly from said clincher s curing portion, sai-:l pin and said threaded hole having axes parallel to the axis of said shaft.

5. A rotary anvil base for a rotary anvil in a stapling machine, said base being made from hard abrasion resisting metal and adapted for use in bearings, said base comprising a cylindrical shaft having a hole therein, said shaft being integrally formed with the corner portion of a substantially quadrant shaped hub, said hub being of uniform thickness and having hatV surfaces thereon perpendicular to the axis of said shaft, the Vflat surface opposite said shaft including a clincher securing portion andl a table portion adjacent thereto, said clinciier securing portion having a threaded hole therein near the circumference of said quadrant shaped hub and two anvil pins'extending outwardly from said clincher securing portion, said anvil pins and said threaded hole having axes parallel to the axis of said shaft.

6. A two-piece rotary anvilcoinprising a hard shaft with a hub thereon, said hub being larger in area than the cross-sectional area of said shaft, said hub having a hard flat abrasion resisting surface thereon opposite said shaft portion, and a separate clincher made from tough spring steel, and means for removably securing said clincher to said hub, said clincher having its grain structure running substantially parallel to its geometric axis and being secured to said hub so as to leave an exposed abrasion resisting table portion on said hub.

'7. A two piece rotary anvil for a stapling machine, said anvil comprising a hard steel anvil base and a spring steel clincher removably secured thereto, said base comprising a shaft having a hub thereon perpendicular to the vaxis of said shaft, said hub having a flat surface opposite said shaft including /a clincher securing portion and -a table portion adjacent thereto, said clincher securing portion being provided with means for removably securing said olincher thereto, said clinoherhaving an upper portion removably secured to said hub and a piercing and clinching portion having its grain structure running substantially parallel to its geometric axis.

8. A two piece rotary anvil for a stapling machine, said anvil comprising an anvil base with a clincher removably secured thereto, said anvil base being made from hard abrasion resisting metal and adapted for use in bearings, said base comprising a shaft having a substantially quadrant shaped hub thereon, said hub having a flat surface thereon perpendicular to the axis of said shaft, said flat surface opposite said shaft including a clincher securing portion and a table portion adjacent thereto, said clincher securing portion having a threaded hole therein adjacent the circumference of said quadrant shaped hub and two anvil pins extendingoutwardly from said clincher securing portion, said anvil pins and said threaded hole having axes parallel to the axis or" said shaft, said separate clincher being made from spring steel and having a fiat upper portion positioned flatly against said staple securing portion, said upper portion having two anvil pin holes therein for receiving said anvil pins and a countersunl; hole in registry with said threaded hole in said hub for receiving a cap screw, said clincher having piercing and clinching means thereon.

9. A removable substantially crescent-shaped clincher for a stapling machine having a pivoted member for receiving said clincher, said clincher comprising an upper securing portion having securing ine-ans therein, a piercing and clinching portion exte ng therefrom, said latter portion being of width than said upper securing portion having piercing means therein, said clineher having grain structure running in a direc n substantially parallel to the geometric axis of said clincher.

le. A removable substantially crescent-shaped eline for stapling machine having a Apivoted member for receiving said clincher, said clincher having tivo sides and comprising an upper securing portion having a plurality of holes therein, a piercing and clinching portion extending therefrom, said latter portion being of less width than said upper securing portion and having piercing means therein, said clincher having its grain structure running in a direction Substantially parallel to the geometric axis of said clincher.

ll. A rotary anvil base made from hard abrasion resisting metal and adapted for use in bearings, said anvil base comprising a shaft with a hub thereon, said hub having a flat surface thereon perpendicular to the axis of said shaft, said hat surface including a clincher securing portion and a table portion, said clincher securing portion having means thereon for securing a clincher thereto.

Name Date Sona-froth May 3, 1949 Number 

